Spring assembly units and method of assembly thereof



May

G. R. BELLGRAU SPRING ASSEMBLY UNITS AND METHOD OF ASSEMBLY THEREOFFiled May 19, 1951 United States Patent SPRING ASSEMBLY UNITS AND METHODOF ASSEMBLY THEREOF George R. Bellgrau, Chicago, Ill., assignor toNachman Corporation, Chicago, 11]., a corporation of IllinoisApplication May 19, 1951, Serial No. 227,240

2 Claims. (Cl. 5-260) My invention relates to spring assembly units anda method of assembling such units. My invention is particularlyapplicable to a spring assembly unit in which a series of helical tiewires are utilized to tie adjacent rows of springs together and to tiethe marginal springs of the group to a border wire extending around theperiphery of the group of springs.

Heretofore in the manufacture of spring assembly units for cushions,sofas, mattresses and the like, it has been the practice to assembleparallel rows of coil springs, to secure one row of springs to the neXtadjacent row at both top and, bottom by means of clips, hog wires, orby. spinning a helical enveloping the adjacent edges of the top coils ofthe rows of springs. Row after row of springs are thus assembled andwhen the unit has a sufiicient number of rows corresponding with thedesired size of the unit, border wires of flat or round wire stock arepositioned overlapping the outer edges of the marginal springs of thegroup, and this border wire is then secured to the coil springs by meansof clips, tie wires, or by spinning two or more helicals enveloping theborder wire and the portions of the coil springs overlapped by oradjacent to the border wire. When the top of the assembly is thuscompleted, the spring unit is turned over and another border wire issecured to the bottom in like manner.

The patent to Gleason No. 2,473,706, of June 21, 1949 discloses a formof prior art spring assembly which has gone into widespread, commercialuse. This patent typifies the prior art constructions wherein thecomplete assembly is first formed as a subassembly-consisting of rows ofcoil springs held together by helical tie'wires and such subassembly issubjected to a series of additional operations in which the top borderframe is attached by helical tie wires and then turned over, and thelower border frame is similarly attached. In commercial practice twohelical tie wires are ordinarily provided for attaching each border wireto the coils of the marginal springs, each of such helical tie wiresstarting at one corner and running along two sides to the diametricallyopposite corner. These helical tie wires for attaching the border wireare therefore of diiferent length than the helical tie wires whichconnect the rows of coil springs of one row to the coil springs of anadjacent row.

An object of my invention is to provide a new and improved constructionand method of assembly whereby the same helical tie wires which connectthe coils of one row with those of an adjacent row also serve to attachthe border wire to the end coils of the rows.

Another object of my invention is to provide a new and improvedconstruction and method of assembly whereby all of the helical tie wiresmay be of the same or substantially the same length.

Another object of my invention is to provide a new and improvedconstruction and method of assembly wherein all of the helical tie wiresmay be started from one side of the complete assembly or part of thehelical tie wires can be started from one side and the remainder startedfrom the other side as desired.

Another object of my invention is to provide a construction and methodof assembly whereby all of the helical tie wires may be started andfinished substantially simultaneously.

Another object of my invention is to provide a new and improvedconstruction and method of assembly whereby the connecting of the rowsof coils and the attachment of the border wire thereto may be effectedsimultaneously.

A further object of my invention is to provide a new and improvedconstruction and method of assembly which permits greater flexibility inmanufacture.

Another object of my invention is to provide a new and improvedconstruction which more readily adapts itself to diiferent loadings andmore fully compensates for shifts in position of loads imposed thereon.

Another object of my invention is to provide a new and improvedconstruction and method of assembly which can be produced at lower costby conventional methods of mass production manufacture.

Other objects and advantages will become apparent as the descriptionproceeds.

In the drawings:

Fig. l is a top plan view of my improved spring assembly unit; and

Fig. 2 is an enlarged fragmentary portion in the upper left-hand cornerof Fig. 1.

Referring to the drawings, it will be seen that my new and improved unitcomprises a plurality of coil springs 10 which may be of anyconventional or suitable type. These springs are arranged in rows asshown, the number of rows and the number of springs in each row beingdetermined by the ultimate size and shape of the spring assembly unitdesired. For example, a spring assembly unit for a seat cushion mighthave the particular number and arrangement of coil springs shown in Fig.1, whereas a similar unit for a mattress ordinarily would have morecoils in each row and many more rows to give the usual rectangular shapeof such structures.

When the coil springs 10 are arranged in rows as shown in the drawing,the upper and lower coils of the springs in each row are insubstantially abutting relationship with the upper and lower coils ofthe springs in each adjacent row. The border frames 12 are preferablyformed of either round or flattened wire and have a rectangular orsquare shape corresponding to the shape of the completed unit. In mostinstances, identical border frames are attached to the top and bottomcoils of the border springs but for certain special purposes, only oneborder frame may be attached in the manner herein set forth and adifferent kind of frame or support may be provided for the base of theassembly unit.

The border frames 12 are attached to the coil springs 10 by helical tiewires 14a, 14b, 14c, 14d, 142, and 14 which may be of the same length orsubstantially so. The tie wires 14b, 14c, 14d, and 14s serve both toconnect abutting coils of springs 10 in adjacent rows and to connect theend springs of one row to a portion of the border frame, whereas helicaltie wires 14a and 14 connect ends of the border frame to the coilsprings of the end rows but do not serve to connect together coilsprings in adjacent rows.

It will be apparent that the helicals 14 can be spun in place commencingfrom either side of the assembly and that great flexibility ispermissible in the manner in which this is accomplished. For example,all of the helicals for connecting the top and bottom border frames tothe coil springs and for'connccting together the several rows of springscan be applied simultaneously, or in groups, or one at a time, as bestsuited to different manufacturing techniques, and this flexibility inmanufacture is an important aspect of my invention.

It will be noted that each helical starts at one side of the assemblyjust beyond the point of maximum overlap of the border frame with a topor bottom coil of the spring at the end of the row. The helical is sospun that it envelops the top or bottom coil of the end spring of therow and the border wire and then proceeds upwardly along the border wirefrom a point just below the point where the border wire overlaps the endcoil of the top row. The helical proceeds around the curve of the borderwire and envelops the border wire and the edge portions of the topconvolutions of all of the coil springs of this row overlapped by theborder wire.

At the other end of the row the helical follows the path of the curvedborder wire and the arc of the end coil to a point just below the pointwhere the coil spring leaves the path of the border wire. This point isapproximately opposite that from which the helical cornmenced. After thehelical wire is thus spun in place, the edges of the helical are foldedback upon the coil and crimped to lock the helical wire in place.

In the second row the helical 14b is spun on to the border wire at apoint just below the point where the border wire overlaps the end coilof the second row and proceeds along the border wire enveloping both theborder wire and the edge of the coil spring overlapped by the borderwire and then proceeds along the curve of the top convolution of the endcoil to a point where the upper edges of the coils of the second rowabut the edges of the coils of the first row. The helical is then movedforwardly to envelop the edges of the top convolutions of the springs ofboth rows. The helical proceeds along this path, enveloping the topconvolutions of the springs of both rows, until it reaches the endspring of the second row where it follows the arc of the top convolutionof the end coil of the second row and cnvelops both the border wire andthe outer edge of this end coil. The helical then proceeds to a pointapproximately opposite that of the point where it commenced. The ends ofthis helical are then folded back to lock the helical in place.

This same procedure is followed for the various rows of the springassembly unit, the last row of springs being secured to the border wirethe same as the first.

With this improved spring assembly unit, it is apparent that I haveprovided a resilient structure in which the springs are secured in placeand prevented from shifting out of substantial alignment and in whichthe individual rows are tied to the border wire and to the adjacent rowsof springs by the same operation. It is also apparent that thisstructure lends itself to a simple assembly in which the border wire androws of springs are secured in place by a small number of spinningoperations as compared with the procedures and practices heretoforeadopted. The structure described above permits the use of many helicalsof the same length and obviates the difiiculties of storage and handlingof many different length helicals as well as the expense of productionthereof.

This construction also provides for a more ready assembly of the unitsince all of the helicals may be attached simultaneously or sequentiallyfrom either side or may be alternated from side to side depending uponthe positioning of the machines for spinning these helicals.

An important feature of my invention is the reduction in cost ofmanufacture. This is due partly to the elimination of steps in theprocess and partly to the elimination of waste. In the prior artprocess, the helicals which connected the rows of coil springs togetherwere made longer than the length of the row and were trimmed at eachend, whereas in my novel assembly such trimming is unnecessary.

Having thus described my invention, what is claimed as new and desiredto be secured by United States Letters Patent is:

1. A spring assembly unit, comprising a group of coil springs arrangedin adjacent rows with the springs in the adjacent rows abutting againsteach other, a border wire extending around the group of springs tangentto and in abutment with the end springs in said rows, and a plurality ofhomogeneous helical tie wires for securely interconnecting said abuttingsprings in said adjacent rows and for securing the end springs in saidrows to said border Wire, each of said helical tie wires being arrangedto extend along a pair of said rows and being coiled around the abuttingsprings in said rows of said pair at the points of abutment between saidsprings, each tie wire also being coiled around each end spring in oneof said rows of said pair between its points of abutment with theadjacent end spring and the border wire, said tie wire being coiledaround the border wire and said end springs of said one row.

2. In a spring assembly unit, the combination comprising a plurality ofcoil springs arranged in two adjacent rows with the adjacent springs inthe respective rows abutting against each other, a border Wire extendingtangent to and abutting against the end springs in the respective rows,a homogeneous helical tie wire extending along said rows and coiledaround said abutting springs at the points of abutment therebetween,said tie wire being coiled around each of the end springs in one of saidrows between the point of abutment with the corresponding spring in theadjacent row and the point of abutment with said border wire, saidhelical tie wire also being coiled around said border wire at its pointof abutment with each of said end springs in said one row.

References Cited in the file of this patent UNITED STATES PATENTS426,022 Jeffery Apr. 22, 1890 1,596,273 Karr Aug. 17, 1926 1,706,889Kroehler Mar. 26, 1929 1,835,819 Stackhouse a- Dec. 8, 1931 2,196,526Gleason Apr. 9, 1940 2,473,706 Gleason June 21, 1949 FOREIGN PATENTS146,692 Great Britain July 15, 1920 391,118 Great Britain Apr. 18, 1933

